Software versions

Python version : 3.9.9 | packaged by conda-forge | (main, Dec 20 2021, 02:41:03)
IPython version : 7.31.0
Tornado version : 6.1
Bokeh version : 2.4.2
BokehJS static path : /home/graingert/miniconda3/envs/dask-distributed/lib/python3.9/site-packages/bokeh/server/static
node.js version : (not installed)
npm version : (not installed)
Operating system : Linux-5.4.0-94-generic-x86_64-with-glibc2.31

Browser name and version

No response

Jupyter notebook / Jupyter Lab version

No response

Expected behavior

>>> from unittest import mock
>>> from bokeh.server.session import ServerSession
>>> session = ServerSession(mock.MagicMock(), mock.MagicMock())
>>> coro = session.with_document_locked()
>>> del coro
<stdin>:1: RuntimeWarning: coroutine 'ServerSession.with_document_locked' was never awaited
>>> 

Observed behavior

>>> from unittest import mock
>>> from bokeh.server.session import ServerSession
>>> session = ServerSession(mock.MagicMock(), mock.MagicMock())
>>> coro = session.with_document_locked()
>>> del coro
<stdin>:1: RuntimeWarning: coroutine '_needs_document_lock.<locals>._needs_document_lock_wrapper' was never awaited
>>> 

Example code

see above

Stack traceback or browser console output

No response

Screenshots

No response